Mine used to do it randomly quite a lot, seemed to be more when the weather was damp, turned out to be the throttle pedal connection behind the bit of carpeted trim on one side of the passenger foot well. I gave it a clean about a couple months ago with an aerosol of IPA and it's not done it since. I would get an OBD adaptor off fleebay and check which error codes its logging it's an easy way to find the cause and always a handy tool to have. Also if you have a can of IPA you can also clean the MAF sensor with it, I wouldn't buy another one without giving cleaning it a try first and definitely not without checking error codes in case it has nothing to do with the MAF. If it does turn out to be the MAF you can get the same bosch part in a smaller housing MUCH cheaper, I think its sold for a vauxhall van or something lol just re use your old housing.